dc electrokinetic transport of cylindrical cells in straight microchannels

Electrokinetic transport of cylindrical cells under dc electric fields in a straight microfluidic channel is experimentally and numerically investigated with emphasis on the dielectrophoretic (DEP) effect on their orientation variations. A two-dimensional multiphysics model, composed of the Navier–Stokes equations for the fluid flow and the Laplace equation for the electric potential defined in an arbitrary Lagrangian–Eulerian framework, is employed to capture the transient electrokinetic motion of cylindrical cells. The numerical predictions of the particle transport are in quantitative agreement with the obtained experimental results, suggesting that the DEP effect should be taken into account to study the electrokinetic transport of cylindrical particles even in a straight microchannel with uniform cross-sectional area. A comprehensive parametric study indicates that cylindrical particles would experience an oscillatory motion under low electric fields. However, they are aligned with their longest axis parallel to the imposed electric field under high electric fields due to the induced DEP effect.     

An integrated group decision-making process for supplier selection and order allocation using multi-attribute utility theory and linear programming

Supplier selection is a complex multi-criteria problem including both quantitative and qualitative factors. In order to select the best suppliers it is necessary to make a trade-off between these factors, some of which may be in conflict and may also be uncertain. In this problem if suppliers have capacity or other different constraints, two problems will exist: which suppliers are best and how much should be purchased from each selected supplier.In this paper an integrated approach of multi-attribute utility theory (MAUT) and linear programming (LP) is proposed for rating and choosing the best suppliers and defining the optimum order quantities among selected ones in order to maximize total additive utility. A numerical example is proposed to illustrate an application of the proposed method.     

Normal delivery induced stress alters glutathione peroxidase and TNF-α in elderly primigravidas mononuclear cells

To probe the glutathione peroxidase (GPx) activity coupled to ROS and TNF-α levels in younger versus elderly primigravidas. Monocytes were isolated from blood of young and elderly primigravidas after 12 hrs, 24 hrs and 14 days postpartum. Age-matched healthy female donors served as controls. Thereafter, the above monocytes were subjected to evaluation of GPx activity, levels of pro-inflammatory cytokine TNF-α and reactivity/specificity towards anti-TNF-α antibody. Suppression in GPx activity with simultaneous enhancement of TNF-α levels in monocytes was observed after 12 hrs and 24 hrs of spontaneous labor pain-induced maternal delivery through normal vaginal route. Conversely, an enhancement of GPx activity and decrease in TNF-α levels were observed on day 14 of postpartum, thereby indicating reversal of the impaired neutralizing mechanisms. The antioxidant network combating ROS was stronger in younger primigravidas. Capability of TNF-α and ROS suppression was somewhat lesser in elderly primigravidas even 14 days of postpartum via normal vaginal route. The capability of GPx activity enhancement with simultaneous suppression in ROS and TNF-α, decreases in elderly primigravidas. This may act as one of the important parameters leading to a variety of complications encountered by elderly primigravidas.     

Optimized sliding mode current controller for power converters with non-minimum phase nature

This paper proposes a unified method to design an optimized type of the hysteresis modulation-based sliding mode current controller for non-minimum phase power converters in continuous conduction mode. The traditional sliding mode controlled converters have a slow transient voltage response at heavy loads, a large overshoot at light loads and during abrupt output resistance variations. To solve these problems, an optimized feedback control scheme is used according to the output resistance to adjust the coefficients of the controller. The basic idea of this controller is to suggest a new way for reduction of the sensitivity function amplitude of the closed loop system. The presented approach is developed for three basic DC/DC converters; i.e. boost, buck-boost and quadratic boost converters. Generally, the certain advantages of the suggested control approach are: (i) a fast transient response can be achieved in heavy load conditions, (ii) the voltage overshoot can be effectively reduced during load variations; (iii) the transient voltage overshoot can be eliminated in light load conditions; (iv) the closed loop control sensitivity can be reduced and therefore, the performance specification of a control system can be improved compared with the conventional sliding mode current control. To show the reliability of the suggested control scheme, simulations and experimental results for the derived systems are developed. Several conditions are performed to confirm the effectiveness of the proposed controller.     

Raising teachers’ voices: an in-depth qualitative inquiry into teachers’ working conditions and professional development needs in Khyber Pakhtunkhwa,a province of Pakistan

This study documented in detail teachers’ voices about their working conditions, professional development needs and opportunities to cater to these needs. The study reported in this paper was conducted as part of a large-scale study that used mixed methods to assess teachers’ professional development needs. The qualitative data reported in this paper were collected using focus group discussion with teachers (N = 481), classroom observation (N = 66), post-observation interviews with teachers (N = 24) and analysis of qualitative responses from survey questionnaires (N = 200). By bringing together a collection of teachers’ voices, the findings of the study illuminate a hope for positive change in teaching and learning in public schools in Khyber Pakhtunkhwa, provided that teachers are genuinely considered as part of the solution and are facilitated with necessary physical and structural resources and psychological incentives. The education system needs to create conditions in schools that support teachers’ work and their continued professional growth.     

Design of a H∞ model reference tracking control for interconnected nonlinear systems by decentralized dynamic output-feedback

This study investigates the problem of robust tracking control for interconnected nonlinear systems affected by uncertainties and external disturbances. The designed H_∞ dynamic output-feedback model reference tracking controller is parameterized in terms of linear matrix inequalities (LMIs), which is formulated within a convex optimization problem readily implementable. The resolution of such a problem, guarantying not only the quadratic stability but also a prescribed performance level of the resulting closed-loop system, enables to calculate concurrently the robust decentralized control and observation gain matrices. The established LMI conditions are computed in a single-step resolution to obtain all the controller/observer parameters and therefore to overcome the problem of iterative algorithm based on a multi-stage resolution leading in most cases to conservative and suboptimal solutions. Numerical simulations on diverse applications ranging from a numerical academic example to coupled inverted double pendulums and a 3-strongly interconnected machine power system are provided to corroborate the merit of the proposed control scheme.     

Study on Impact of Iron and Folic Acid on the Plasma Trace Minerals in Pregnant Anemic Women

Iron deficiency anemia is one of the causes that lead to significant mortality and morbidity among pregnant women and fetus. The present study was undertaken to explore oral iron supplementation can modify the metal contents in pregnant anemic women. Iron and folic acid supplementations was given to 500 anemic women (mild = 200, moderate = 200, and severe = 100) and 100 age matched non-anemic controls daily for 100 days. Blood index values and plasma trace minerals were estimated as per standard protocols. Haemoglobin and ferritin levels were found significantly increased (p < 0.001) in anemic and control subjects after treatment. Moreover, the serum transferring receptor levels and total iron binding capacity were found significantly decreased in all treated groups. Iron (Fe), zinc (Zn) and copper (Cu) levels were found increased (p < 0.01) after oral iron supplementation groups. Moreover, selenium (Se) manganese (Mn) and were found to be decreased in all treated groups. Data provides the conclusion that iron and folic acid supplementation recovered the essential trace minerals, except manganese, which may lead to various complications including peroxidation of vital body molecules resulting in increased risk for pregnant women as well as fetus.     

Urinary Urea,Uric Acid and Hippuric Acid as Potential Biomarkers in Multiple Sclerosis Patients

Urine is a proven source of metabolite biomarkers and has the potential to be a rapid, noninvasive, inexpensive, and efficient diagnostic tool for various human diseases. Despite these advantages, urine is an under-investigated source of biomarkers for multiple sclerosis (MS). The objective was to investigate the level of some urinary metabolites (urea, uric acid and hippuric acid) in patients with MS and correlate their levels to the severity of the disease, MS subtypes and MS treatment. The urine samples were collected from 73 MS patients-48 with RRMS and 25 with SPMS- and age matched 75 healthy controls. The values of urinary urea, uric acid and hippuric acid in MS patients were significantly decreased, and these metabolites in SPMS pattern showed significantly decrease than RRMS pattern. Also showed significant inverse correlation with expanded disability status scale and number of relapses. Accordingly, they may act as a potential urinary biomarkers for MS, and correlate to disease progression.     

Robust simultaneous fault detection and control for a class of nonlinear stochastic switched delay systems under asynchronous switching

This paper concerns the simultaneous fault detection and control (SFDC) problem for a class of nonlinear stochastic switched systems with time-varying state delay and parameter uncertainties. The switching signal of detector/controller unit (DCU) is assumed to be with switching delay, which results in the asynchronous switching between the subsystems and DCU. By constructing a switching strategy depending on the state and switching delays, new sufficient conditions expressed by a set of linear matrix inequalities (LMIs) is derived to design DCU gains. This problem is formulated as an H_∞ optimization problem and both mean square exponential stability and fault detection of augmented system are considered. A numerical example is finally exploited to verify the effectiveness and potential of the achieved scheme.     

和田地区中小学"维汉"双语教育三种主要模式及分析

科学的双语教育理论应该建立在科学地划分双语教育类型的基础上.文章按照学校的语言文化环境将和田地区中小学的双语教育模式大体分为民族学校模式、汉族学校模式、民汉合校模式等三个类型,从理论依据、教学目标、操作程序、操作策略等角度对其进行分析.